1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T P.1100 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2017) SERIES P: TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Communications involving vehicles Narrowband hands-free communication i
2、n motor vehicles Recommendation ITU-T P.1100 ITU-T P-SERIES RECOMMENDATIONS TELEPHONE TRANSMISSION QUALITY, TELEPHONE INSTALLATIONS, LOCAL LINE NETWORKS Vocabulary and effects of transmission parameters on customer opinion of transmission quality Series P.10 Voice terminal characteristics Series P.3
3、0 P.300 Reference systems Series P.40 Objective measuring apparatus Series P.50 P.500 Objective electro-acoustical measurements Series P.60 Measurements related to speech loudness Series P.70 Methods for objective and subjective assessment of speech quality Series P.80 Methods for objective and subj
4、ective assessment of speech and video quality Series P.800 Audiovisual quality in multimedia services Series P.900 Transmission performance and QoS aspects of IP end-points Series P.1000 Communications involving vehicles Series P.1100 Models and tools for quality assessment of streamed media Series
5、P.1200 Telemeeting assessment Series P.1300 Statistical analysis, evaluation and reporting guidelines of quality measurements Series P.1400 Methods for objective and subjective assessment of quality of services other than speech and video Series P.1500 For further details, please refer to the list o
6、f ITU-T Recommendations. Rec. ITU-T P.1100 (03/2017) i Recommendation ITU-T P.1100 Narrowband hands-free communication in motor vehicles Summary Recommendation ITU-T P.1100 describes performance requirements and test methods for narrowband hands-free communication in vehicles. This Recommendation co
7、vers: built-in hands-free systems, after-market hands-free car kits, corded headsets, and wireless headsets, to be used in vehicles for communication while driving. This Recommendation addresses the test of complete systems, as well as the subsystems of hands-free microphones and telephones with sho
8、rt-range wireless transmission links used to interconnect the hands-free system to the mobile network. For testing, the test set-up and the recommended environmental conditions are described. The methods, analysis and performance parameters described in this Recommendation are based on test signals
9、and test procedures defined in Recommendations ITU-T P.501, ITU-T P.502, ITU-T P.340 and ITU-T P.380. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T P.1100 2008-10-22 12 11.1002/1000/9545 2.0 ITU-T P.1100 2011-03-01 12 11.1002/1000/11078 3.0 ITU-T P.1100 2015-01-13 12 11.10
10、02/1000/12415 4.0 ITU-T P.1100 2017-03-01 12 11.1002/1000/13174 Keywords Hands-free, headset, motor vehicle, quality of service, QoS. _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example,
11、 http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T P.1100 (03/2017) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardizati
12、on Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meet
13、s every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts p
14、urview, the necessary standards are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is v
15、oluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ an
16、d the negative equivalents are used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may invo
17、lve the use of a claimed Intellectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Reco
18、mmendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database a
19、t http:/www.itu.int/ITU-T/ipr/. ITU 2017 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T P.1100 (03/2017) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 3 3.1 Terms defined els
20、ewhere 3 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 4 5 Conventions 6 6 How to use this Recommendation 6 6.1 Determining compliance with this Recommendation 6 6.2 Testing at different stages of the development cycle . 7 7 Test arrangement 8 7.1 Test arrangement in a ca
21、r . 9 8 Digital interfaces for development, debugging and testing 13 8.1 Interfaces and access points 13 8.2 Test set-up and tests 15 9 Test signals and test signal levels . 17 9.1 Signals 17 9.2 Background noise signals . 17 10 Measurement parameters and requirements for microphones used in speaker
22、phone hands-free systems 19 10.1 Microphone measurements in anechoic conditions 19 10.2 Microphone measurements in the car . 22 11 Measurement parameters and requirements for hands-free terminals 27 11.1 Preparation measurements 27 11.2 Delay . 27 11.3 Loudness ratings . 29 11.4 Sensitivity frequenc
23、y responses . 32 11.5 Speech quality during single talk . 35 11.6 Listening speech quality stability . 36 11.7 Idle channel noise . 38 11.8 Out-of-band signals 40 11.9 Distortion in send . 41 11.10 Distortion in receive . 41 11.11 Echo performance . 42 11.12 Double-talk performance 52 11.13 Backgrou
24、nd noise transmission 58 iv Rec. ITU-T P.1100 (03/2017) Page 12 Verification of the transmission performance of short-range wireless (SRW) transmission enabled phones 62 12.1 Interface definition and calibration 62 12.2 SRW loudness ratings . 65 12.3 SRW sensitivity frequency responses 68 12.4 SRW n
25、oise cancellation test in send . 69 12.5 SRW speech quality during single talk 70 13 Car-to-car communication 73 14 Guidance on subjective testing . 73 15 Corded headsets 78 15.1 Connector type 78 15.2 Connector wiring and electrical specifications . 78 15.3 Headset receive characteristics . 78 15.4
26、 Headset transmit characteristics . 78 15.5 Standard behaviour in the presence of corded headsets . 78 16 Wireless headsets 78 16.1 Wireless headset types 79 16.2 Test methodology for verification of standard behaviour 79 16.3 Standard behaviour in the presence of wireless headsets . 79 Annex A Spee
27、ch quality measurements 80 Annex B Principles of relative approach 82 Annex C Example of a questionnaire for subjective testing . 84 C.1 Performance rating overview 84 C.2 Test categories and rating types . 84 C.3 Speech and background noise quality in send direction . 86 C.4 Speech quality in recei
28、ve direction (in the car under test) . 91 C.5 Echo cancellation performance 93 C.6 Hands-free system stability tests (car-to-car) . 99 Annex D Standard set of user scenarios 101 Annex E System stability with insufficient far-end echo loss 103 Annex F Microphone related sound field reproduction techn
29、ique Multipoint noise simulation method (MPNS) 105 F.1 Loudspeaker setup in the car 105 F.2 Microphone setup in the car . 105 F.3 Background noise recordings and reference noise . 106 F.4 Equalization 106 F.5 Accuracy of the equalization 106 Rec. ITU-T P.1100 (03/2017) v Page Appendix I A method to
30、determine the listening speech quality 108 I.1 One-way speech quality in send . 108 I.2 One-way speech quality in receive . 108 Bibliography. 109 Rec. ITU-T P.1100 (03/2017) 1 Recommendation ITU-T P.1100 Narrowband hands-free communication in motor vehicles 1 Scope The aim of this Recommendation is
31、to define use cases and test methods for narrowband hands-free communication in vehicles. This Recommendation covers: built-in hands-free systems, after-market hands-free car kits, corded headsets, and wireless headsets, to be used in vehicles for communication while driving. This Recommendation add
32、resses the test of complete systems, as well as the subsystems of hands-free microphones and telephones with short-range wireless transmission links used to interconnect the hands-free system to the mobile network. For testing, the test set-up and the recommended environmental conditions are describ
33、ed. The methods, analysis and performance parameters described in this Recommendation are based on test signals and test procedures defined in ITU-T P.501, ITU-T P.502, ITU-T P.340 and ITU-T P.380. Although important, subjective testing is outside the scope of this Recommendation; some guidance on h
34、ow to conduct subjective tests can be found in clause 14. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All R
35、ecommendations and other references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regul
36、arly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.100.1 Recommendation ITU-T G.100.1 (2015), The use of the decibel and of relative levels in speechband telecommunications. ITU-T G.111 Recommend
37、ation ITU-T G.111 (1993), Loudness ratings (LRs) in an international connection. ITU-T G.122 Recommendation ITU-T G.122 (in force), Influence of national systems on stability and talker echo in international connections. ITU-T G.711 Recommendation ITU-T G.711 (in force), Pulse code modulation (PCM)
38、of voice frequencies. ITU-T P.48 Recommendation ITU-T P.48 (in force), Specification for an intermediate reference system. 2 Rec. ITU-T P.1100 (03/2017) ITU-T P.51 Recommendation ITU-T P.51 (1996), Artificial mouth. ITU-T P.56 Recommendation ITU-T P.56 (in force), Objective measurement of active spe
39、ech level. ITU-T P.57 Recommendation ITU-T P.57 (in force), Artificial ears. ITU-T P.58 Recommendation ITU-T P.58 (in force), Head and torso simulator for telephonometry. ITU-T P.64 Recommendation ITU-T P.64 (in force), Determination of sensitivity/frequency characteristics of local telephone system
40、s. ITU-T P.79 Recommendation ITU-T P.79 (in force), Calculation of loudness ratings for telephone sets. ITU-T P.340 Recommendation ITU-T P.340 (in force), Transmission characteristics and speech quality parameters of hands-free terminals. ITU-T P.380 Recommendation ITU-T P.380 (in force), Electro-ac
41、oustic measurements on headsets. ITU-T P.501 Recommendation ITU-T P.501 (in force), Test signals for use in telephonometry. ITU-T P.502 Recommendation ITU-T P.502 (in force), Objective test methods for speech communication systems using complex test signals. ITU-T P.581 Recommendation ITU-T P.581 (2
42、000), Use of head and torso simulator (HATS) for hands-free terminal testing. ITU-T P.800 Recommendation ITU-T P.800 (in force), Methods for subjective determination of transmission quality. ITU-T P.800.1 Recommendation ITU-T P.800.1 (in force), Mean Opinion Score (MOS) terminology. ITU-T P.863 Reco
43、mmendation ITU-T P.863 (in force), Perceptual objective listening quality assessment. ITU-T P.863.1 Recommendation ITU-T P.863.1 (in force), Application guide for Recommendation ITU-T P.863.1. IEC 60268-4 IEC 60268-4 (2014), Sound system equipment Part 4: Microphones. IEC 61260-1 IEC 61260-1 (1995)
44、Electroacoustics - Octave-band and fractional-octave-band filters Part 1: Specifications. Rec. ITU-T P.1100 (03/2017) 3 3 Definitions 3.1 Terms defined elsewhere None. 3.2 Terms defined in this Recommendation This Recommendation defines the following terms: 3.2.1 artificial ear: Device incorporating
45、 an acoustic coupler and a calibrated microphone for the measurement of sound pressure and which has an overall acoustic impedance similar to that of the median adult human ear over a given frequency band. 3.2.2 codec: Combination of an analogue-to-digital encoder and a digital-to-analogue decoder o
46、perating in opposite directions of transmission in the same equipment. 3.2.3 composite source signal (CSS): Signal composed in time by various signal elements. 3.2.4 diffuse-field equalization: Equalization of the HATS sound pick-up, equalization of the difference, in dB, between the spectrum level
47、of the acoustic pressure at the ear-drum reference Point (DRP) and the spectrum level of the acoustic pressure at the HATS reference point (HRP) in a diffuse sound field with the HATS absent using the reverse nominal curve given in Table 3 of ITU-T P.58. 3.2.5 ear-drum reference point (DRP): Point l
48、ocated at the end of the ear canal, corresponding to the ear-drum position. 3.2.6 free-field equalization: The transfer characteristics of the artificial head are equalized in such a way that, for a frontal sound incidence in anechoic conditions, the frequency response of the artificial head is flat
49、. This equalization is specific to the HATS used. 3.2.7 free-field reference point: Point located in the free sound field, at a distance of at least 1.5 m from a sound source radiating in free air (in case of a head and torso simulator (HATS) in the centre of the artificial head with no artificial head present). 3.2.8 hands-free reference point (HFRP): A point located on the axis of the artificial mouth, at 50 cm from the outer plane of
